Cardiovascular disease (CVD) is the leading cause of death and the most expensive disease in the U.S. Many patients are asymptomatic before the first serious and often fatal event. Unlike cancers in which numerous underlying pathologies exist, the majority of CVD is caused by atherosclerosis. New solutions for early detection and treatment monitoring of atherosclerosis present major opportunities for prevention of CVD. In addition to saving lives, there is the potential for significant reductions in healthcare costs. It is widely accepted that endothelial dysfunction is the gateway to atherosclerosis. Opinion leaders have described endothelial function as the "barometer of cardiovascular health" [1]. Current methods of noninvasive assessment of endothelial function are based on measuring arterial response to reactive hyperemia [31-33]. Endothelix, Inc. is developing a low-cost, non-invasive, non-imaging screening test for CVD (Digital Thermal Monitoring, DTM) based on measuring fingertip thermal reactivity during the hyperemic response to brachial artery occlusion and release. The test involves the inflation of a blood pressure cuff on the arm for 2-5 minutes followed by immediate deflation, while monitoring temperature changes in the index fingers of the study and contralateral hands. Preliminary studies with an early prototype of the DTM device in two centers have shown that fingertip thermal reactivity is lower in patients with 1) known diagnosis of coronary heart disease, 2) extensive sub-clinical coronary atherosclerosis, and 3) high risk factors for atherosclerosis. Endothelix has received indications of a strong interest in the device after presentations at national cardiovascular conventions. The proposed VENDYS device will be suitable for more detailed investigations of this phenomenon at clinics, medical centers, and medical research facilities worldwide. Continued successful results from VENDYS studies and further refinement of the DTM technology can lead to eventual large scale usage of the device including in outpatient clinics and ultimately for home-based monitoring. The specific aims of the proposed work are to 1) Develop a multi-channel DTM module that can measure fingertip temperatures during brachial artery occlusion and release to an accuracy of 0.01[unreadable]C. Success criteria are the demonstration of successful operation and performance of the software management of the DTM module, the cuff management (automated inflation and deflation) module, and the graphical user interface for data entry, display and reporting of the test; and 2) Validate the performance of the integrated component modules through comparison with the existing prototype devices and repeatability testing. Success criteria are that the device perform according to the design specifications when used by medical personnel with no specialized electronics or computer knowledge This grant application proposes to build a commercial version (VENDYSTM) of the early DTM prototype which can then be tested in large multi-center studies, particularly in pharmaceutical clinical trials and long term epidemiologic studies. Upon successful conclusion of these trials, the company intends to commercialize the device as a low-cost, non-invasive, non-imaging vascular stress test. The company envisions that DTM technology would be incorporated in existing blood pressure devices as an affordable and easy-to-use tool for hospital and home based vascular health monitoring. PUBLIC HEALTH RELEVANCE: Widespread clinical evaluation of endothelial dysfunction - an early and accurate indicator of cardiovascular disease - is currently hindered by the absence of an affordable, accurate, and non-invasive measurement technology. The proposed work seeks to refine and realize in a commercially viable product a novel technique of endothelial dysfunction assessment via the non-invasive, localized measurement of finger temperature during a controlled testing protocol involving the temporary occlusion of a subject's arm. Once successfully implemented, such a digital temperature measurement device is foreseen to find common use in clinical practice - contributing to the early detection and monitoring of cardiovascular disease, and then to increased patient longevity and reduced healthcare costs. [unreadable] [unreadable] [unreadable]